1. Field of the Invention
The present invention relates to a seat angle regulating apparatus.
2. Description of the Prior Art
An example of a conventional seat angle regulating apparatus's arrangement is shown in FIG. 12 and FIG. 13. The conventional seat angle apparatus has the following:
an upper arm 2 mounted to a seat back 12 of a seat 1,
a lower arm 3 mounted to a seat cushion 12 of a seat 1,
an internal gear 21 and an external gear 31, having teeth at least one tooth less than the number of teeth of the internal gear 21, in mesh between the upper arm 2 and the lower arm 3 for regulating the relative angle between the upper arm 2 and the lower arm 3,
an angle regulating unit 4a having an eccentric shaft 40a for rotatably supporting the internal gear 21 at a concentric portion 401 thereof and rotatably supporting the external gear 31 at an eccentric portion 402 thereof and engaging the internal gear 21 and the external gear 31 in mesh, and a motor 41e for rotating the eccentric shaft 40a, and
a locking unit 5a for engaging and disengaging said angle regulating unit 4a to and from either of said upper arm 2 or said lower arm 3 and changing the relative angle between said upper arm 2 and said lower arm 3 independently of said angle regulating unit 4a when said angle regulating unit 4a is disengaged.
Further, a switch mechanism 9 for turning the motor 41e on and off is provided to the conventional seat angle regulating apparatus. The switch mechanism 9 has three terminals 91 retained on the upper arm 2 and an arc-shaped terminal plate 92 fixed on the lower arm 3. The terminals 91 move with the upper arm 2 while contacting with the arc-shaped terminal plate 92. The switch mechanism 9 works as follows:
When the terminal 91 at the left hand side in FIG. 12 leaves the arc-shaped terminal plate 92, an electric current supply to the motor 41e stops and the step-less forward reclining stops. When the terminal 91 at the right hand side in FIG. 12 leaves the arc-shaped terminal plate 92, the electric current supply to the motor 41e also stops and the step-less backward reclining stops. Thus the seat angle regulating unit regulates the step-less reclining range of the seat back 12 of the seat 1.
Furthermore, the full-forward-reclining locking state can be released by operating the locking unit 5a. The locking unit 5a has an operating lever 51a, a locking pole 52a, a tension spring 53a, and a pole shaft 54b. When the operating lever 51a is pulled, the locking pole 52a turns in the counterclockwise direction in FIG. 12 around the pole shaft 54b. Then a projected portion of the external gear 31 is disengaged from the pole 52a. And the upper arm 2 and the external gear 31 are reclined like one body fully in the counterclockwise direction in FIG. 12; i.e. forward direction, because the upper arm 2 is urged in the counterclockwise direction by the spiral spring 22 (shown in FIG. 13).